Tracking the Elusive
Martial Eagle Solitary, silent, a fleck among the clouds, the eagle rides the air currents above the Maasai Mara National Reserve in Kenya. Two miles below, UK graduate student Stratton Hatfield bounces along rough trails in a Land Rover, more visible to the eagle than the eagle is to him. For 10 to 12 hours at a time, he searches along with his two Kenyan Bird of Prey Trust mentors, Simon Thomsett and Shiv Kapila, craning their necks to catch a glimpse of an elusive predator, the martial eagle. The martial is the fifth largest eagle in the world, with a wingspan of 6 to 9 feet. The females can kill prey weighing up to 30 pounds; the smaller males, less. Martials are on the decline, and Hatfield is determined to learn as much as he can about the top avian predator in the African savannah ecosystem. His current research project, using transmitters and camera traps to track and study the birds within the reserve and surrounding communities and conservancies, is part of his master's degree work in wildlife conservation in the UK Department of Forestry. “Part of the reason I can do what I do is the Maasai communities surrounding the Mara have leased their land for conservation,” said Hatfield, who has been fascinated by birds since he was a child growing up in Angola, Zimbabwe, and Kenya. “I'm not seeing this study as just a degree. I'm seeing raptor conservation as something I hope to dedicate a large part of my life towards,” he said. 24
(l-r) Shiv Kapila and Stratton Hatfield examine a martial eagle before releasing it, part of Hatfield's research for his master's degree in CAFE's Department of Forestry.
Hatfield's passion and love for his homeland is evident in the way he describes the Mara, an enormous conservation area that is part of the Greater Mara Serengeti ecosystem. “It is an amazingly open tall grass prairie, with rocky outcrops and hills and forests, with 100 thousand wildebeest and a pride of lions on the rocks, a herd of elephants under the trees, giraffes browsing by the river. It's beautiful. You add to that Maasai herdsmen, 200 cattle walking through the plains, and it's breathtaking.” Outside that idyllic scene, though, population growth in Africa is monumental, which can seriously compromise the natural world.
John Cox, assistant professor of wildlife and conservation in the Forestry Department and Hatfield's graduate professor, links biodiversity loss not only with population growth but also climate change. “Coupled with desertification, temperatures are getting hotter and rain patterns are changing. That can alter animal migrations and human land-use patterns,” he said. “It's a major global problem and a challenge that we can't afford to ignore.” Because martials occur at very low density—one pair of birds may occupy 150 square miles of territory— much remains unknown about them. Cox said Hatfield's study, in collaboration with Kaipila, Thomsett, Dr. Ralph Buij of the University of Wageningen, and Dr. Munir Verani of the East African Peregrine Fund, will lead to understanding the eagle's habitat needs. The camera traps have caught some remarkable pictures of nesting pairs. Away from the nest, the team collects data through the use of ultralight, solar-powered transmitters that fit like backpacks on the birds. Weak leather links built into the straps will cause the transmitters to detach after a year or two. With points recorded up to every 30 seconds, Hatfield and his colleagues can identify every tree where the bird roosts, how it flies to that tree, and how fast and high it flies—data that up until now was impossible to gather. It's work that stands to greatly benefit the martial eagle, a very special symbol of Africa. –Carol Lea Spence